In a conventional arrangement for assembling pipes of various lengths with use of fittings, several types of split fittings are combined at the ends of pipes or in the middle of a pipe. Each of these split fittings has pipe support sections whose dimensions and shape conform to the components (i.e. pipes), and forms tubular sections when combined with each other. Into these tubular sections, pipes are inserted and fixed by bolts and nuts in a clamped manner. As is already known, this structure is utilized to assemble a plurality of pipes in an orthogonal arrangement, freely in the lengthwise and widthwise directions.
As an example of the prior art, Japanese Examined Patent Publication No. S53-25170 discloses a pipe connection method and a fitting therefor. This method utilizes a split fitting which has an arc-shaped (or half arc-shaped, ¼ arc-shaped) grip and half pipe-shaped pipe sections consecutively extending therefrom. While a pipe P1 is inserted into the grip, a pipe P2 is fitted into the opposing pipe sections from a different direction. To fix these pipes, the fitting is tightly clamped in the pipe sections, at a position closer to the grip.
To give another example, Japanese Utility Model Laid-open Publication No. H1-92507 discloses a pipe connector which comprises two connector members and a bolt and nut for fixing them. Each of the connector members has half-cylindrical pipe support recesses which are oriented perpendicularly to each other, such that the recesses form a part of near-cylindrical pipe support sections when the connector members are mated together. One of the half-cylindrical pipe recesses includes a slot which extends along the length of the recess. In this slot, the bolt can be fixed displaceably along the slot.
In order to combine and fix the split fitting (or the connector) by a bolt and nut, Japanese Examined Patent Publication No. S53-25170 teaches to pass a bolt and nut 6 through a hole 5 formed in each half pipe-shaped pipe section, thereby fixing the split fitting at a desired position on the pipe P1. Similarly, regarding Japanese Utility Model Laid-open Publication No. H1-92507, the hole for a tightening bolt is designed in the form of a slot, for convenience of installation. By means of the tightening bolt, the pipe surface is fixedly clamped in the half-cylindrical pipe support recesses. Thus, in both examples, the components are fixed by a friction force which is generated between the pipe support sections and the pipes by tightening a bolt and nut.
However, some problems tend to arise when the fitting is mounted on the pipe P1 according to Japanese Examined Patent Publication No. S53-25170, and when the fitting (half-cylindrical pipe support recesses) is attached to the pipe according to Japanese Utility Model Laid-open Publication No. H1-92507. In both cases, a worker locates and fixes the fitting at an approximate installation position, depending on his/her sense. By way of example, when the fitting is equipped to the pipe P1 of the former reference or to the pipe of the latter reference in order to assemble a shelf, if the installation operation lacks precision in height dimension, the assembled shelf will wobble or show other defects. Thus, as far as the installation operation relies on worker's sense, it is difficult to conduct exact height adjustment.
The present invention is made to solve such problems. An object of the present invention is to provide a pipe fitting which connects the pipe fitting to a pipe with a good dimensional precision, thus ensuring an exact assembly operation, and which can fix the pipe and the pipe fitting together, in a simple manner and with a reinforcing effect. Another object of the present invention is to provide an assembly using such pipe fittings.